Asynchronous sockets

Hmm done a lot of reserach on this, but still I cannot find out why this is failing...


Basically I have set up one test program to have one listening socket, and one client socket, I use Telnet to contact my test program, it works fine, has async sockets, and whenever I type it spits stuff onto the screen.

Now to the problem:

I have another program which uses an STL map to hold all the incoming sockets...

here's the relevant socket handling code..

Code:

HRESULT Cappsvr2View::socketMsg(WPARAM wp, LPARAM lp)
{
	if(WSAGETSELECTERROR(lp))
	{
		WSACleanup();
		TRACE0("Get select error, bailing out!");
		exit(1);
	}
	int recvd = 0;
	int sockNum = (int)wp;
	int tsockNum = 0;
	char * tmpbuf;
	char buf[100];
	ZeroMemory((void *)buf, 100);
	sockaddr_in clientSock;
	int lenclient = sizeof(clientSock);
	int errs = 0;
	CString tmp;
	LANCLIENT * tmpclient = new LANCLIENT;
	std::map<int, LANCLIENT*>::iterator it;

	switch(WSAGETSELECTEVENT(lp))
	{
		case FD_ACCEPT:
			//AfxMessageBox("Client connecting!");
			tmpclient->ClientSocket = accept(wp, (LPSOCKADDR)&clientSock, &lenclient);
			errs = WSAAsyncSelect(tmpclient->ClientSocket, GetSafeHwnd(), WM_ONSOCKET, FD_WRITE | FD_READ | FD_CLOSE);
			TRACE1("Error code for AsyncSelect is %d", errs);
			if(INVALID_SOCKET == tmpclient->ClientSocket)
			{
				errs = WSAGetLastError();
				TRACE1("ERROR: Socket error: %d\n", errs);
				WSACleanup();
			}
			tmpclient->clnt_addr.sin_addr   = clientSock.sin_addr;
			tmpclient->clnt_addr.sin_family = clientSock.sin_family;
			tmpclient->clnt_addr.sin_port   = clientSock.sin_port;
			tmpclient->currentMsg = "";
			connections[(int)tmpclient->ClientSocket] = tmpclient;
			TRACE2("Client Socket is %d and sockNum is %d\n", 
				connections[(int)tmpclient->ClientSocket]->ClientSocket, sockNum);
			
			TRACE1("Current sockets is %d", connections[(int)tmpclient->ClientSocket]->ClientSocket);
			break;
		case FD_READ:		
			recvd = recv((SOCKET)wp, buf, (int)strlen(buf), 0);
			//TRACE2("Socket num is %d and wp is %d", connections[sockNum]->ClientSocket, (int)wp);
			errs = WSAGetLastError();
			//send(connections[sockNum]->ClientSocket, "welcome\n", (int)strlen("welcome\n"), 0);

			if(recvd == SOCKET_ERROR)
			{
				recvd = WSAGetLastError();
				TRACE1("Error with error code %d", recvd);
			}
			else if(errs == WSAEWOULDBLOCK)
			{
				TRACE0("Getting would block error!");
			}
			else if(recvd > 0)
			{
				
				buf[recvd] = '\0';
				tmpbuf = new char[(int)strlen(buf) + 1];
				strcpy(tmpbuf, buf);
				connections[sockNum]->currentMsg += tmpbuf;
				TRACE1("We received %s", tmp);
				//send(Clients[clientCount-1], tmpbuf, (int)strlen(tmpbuf), 0);
				send(wp, tmpbuf, (int)strlen(tmpbuf), 0);
				delete tmpbuf;
				tmpbuf = NULL;
			}
			//AfxMessageBox(buf); 
			break;
		case FD_WRITE:
			it = connections.begin();
			while(it != connections.end())
			{
				send(it->second->ClientSocket, "Hello 2 you!\n", (int)strlen("Hello 2 you!\n"),0);
				it++;
			}
			break;
		case FD_CLOSE:
			AfxMessageBox("Client terminated connection!");
			break;

		default:
			break;
	}
	//delete tmpclient;
	//tmpclient = NULL;
	return 1;
}

here's the struct LANCLIENT

Code:

struct LANCLIENT
	{
		int InUse;
		SOCKET ClientSocket;
		struct sockaddr_in clnt_addr;
		CString currentMsg;
	};

I just lose the ability to talk with the telnet client when I use the map, perhaps I am being an idiot and not finding what I need to know, but all I wanted to do was accumulate what the telnet client typed for the moment, any help would be much appreciated, thanks!

Also whenever I type in the telnet client field, I get the FD_READ message, but it always contains 0 bytes when I do a recv... which I read means basically the connection is terminated.

recvd = recv((SOCKET)wp, buf, (int)strlen(buf), 0);

You've already Zeromemoried buf, so strlen is going to return zero - you're telling recv your buffer length is zero! Try

recvd = recv((SOCKET)wp, buf, sizeof(buf), 0);

Also, you don't need to zero the buffer - don't treat it like a c-string, because it's not - you'll run into problems (e.g. what if the client sends a null as part of the data?).

ahhh thanks I had read that you should always zeromemory it, but thats what I get for blindly following all forum advice that worked like a charm, I didn't realize that was the whole problem. Thanks a bunch

Not sure that's the whole problem, I haven't looked very hard

hehe well it certainly worked, and it makes sense... but I wasn't really thinking about it beforehand. however if you spot something glaringly bad or bad codewise feel free to let me know